Plugboard arrangement



Dec. 28, 1948. J. F. MERKEL PLUG BOARD ARRANGEMENTS- 2 SheetS -Sheet 1 Filed Nv. 2s, 194a i o 65 H 0 6% @F@ E i- Zhmeutor 5 v 72M 4%. @4510,

w attorney Dec. 2s, 1.948. JJF. MERKEL 2,457,703

' PLUG BOARD ARRANGEMENTS w Filed Nov. 23, 1946 X -2 Sheets-Sheet 2' FIG.5.

FIG. 4.

'WAZM H15 ATTORNEY of the general character disclosed in my prior Patent No. 2,258,122, dated October 7, 1941, to which reference is to be made for a more complete disclosure as tothe relay structure. However, for an understanding of the present invention,it is believed suilicient to assume the movable contacts ll, connected by the pusher l2, to be actuated by the electro-magnetic attraction of an armature to selectively close front contacts l3 and back contacts l4 in accordance with the respective energization or deenergization of the relay windings I5 and It. The respective contacts I, I3 and M are secured within the contact block I! of insulating material, and electrical connections to such contacts are provided by the coupling of contact tips l8 of such contacts, arranged in pairs and in vertical and horizontal rows, with the respective contacts C in the form of contact strips which are detachably secured within the plug board PB.

The plug board PB has laterally spaced rods l9 suitably secured thereto as by the nuts 20 and 2i at the respective front and back sides of the plug board. These rods serve as a means for alignment of the contact tips of the relay R when it is being coupled to the plug board PB, and the relay R is securely held in its coupled position by suitable thumb nuts 22 threaded on to the ends of the rods l9 and bearing on the ends of the sleeves 23 which are a part of the relay R.

Near the bottom of the plug board PB is secured a test terminal T having a structure similar to that disclosed in my above mentioned patent except that the elongation of the terminal at the front of the plug board is preferably provided as shown to render the terminal more readily accessible from the front of the plug board.

The plug board PB as provided in this embodiment of the present invention is arranged to accommodate nine pairs of contacts C, three rows of three pairs in each row, as illustrated in Fig. 2 for coupling with contact tips 18 of the relay R. In addition to these contacts, the respective contact arrangements are provided in the lower portion of the plug board for connection to the respective contact tips 24 associated with the respective ends of the windings of the relay R. Although these contact arrangements are shown disposed at an angle, it is to be understood that this position is particularly selected to facilitate in providing maximum clearance of the contacts from other parts in the structure of the relay R in this embodiment of the present invention, and that the contact arrangements may be otherwise disposed in accordance with the requirements of practice. It is to these contact arrangements that wiring connections are made for the control of the energizationof the windings of the relay. Thus it is schematically illustrated, for example, that the windings are connected in series and energized by the battery 25 upon the closure of the control switch 26.

To consider the structure in detail of a typical plug and contact ogranzation, reference is made to Fig. 3 in which it is shown that the contacts C and the plug P are inserted within substantially rectangular openings 21 in the plug board PB, the plug P being suitably secured, as by cement, in the slots 63 of the plug board PB. One contact C is disposed above the plug P, and another contact C is disposed below the plug P in each opening 21.

. Each of the contacts C is substantially QQ 4 tangular in shape, and is formed preferably of a strip of resilient material having low electrical contact resistance such, for example, as Phosphor bronze. It is adapted by suitable ears and sleeves to have secured thereto two wires, one along each side of the contact. Thus the ears 28 at opposite sides of the contact C are adapted by being formed inwardly, at an angle to be readily clinched down upon a wire to securely hold it tightly against the base of the contact as shown for the clamping of the wire 29 in Fig. 3. Adjacent the ears 28 are shorter ears 30 formed upwardly for the purpose of providing shoulders against which the bare wires may be bonded as by sweating or welding as more clearly illustrated in Fig. 5. I

For providing additional support at the ends of wires connected to the contact C to reduce to a minimum the possibility of the breaking of strands at the point of their connection to the contact by the flexing of the wires, the sleeves 3! are provided at the opposite right-hand corners of the contact C of a diameter to receive insulated wires and thus limit the flexing of the wire at the point of its connection to the contact C. With reference to Fig. 3 it will be noted that the sleeve 3| is preferably formed so as to allow the clinching of the sleeve on to the insulated wire with a suitable tool if desired.

The contact C has a spring detent 32 formed downwardly and extending longitudinally near the center of the contact C. It is preferably formed as a part of the contact C as by the piercing of the contact C by a U-shaped longitudinal cut extending to the right of the small holes 33 which are provided foraccurately locating the starting point of the pierced section.

The contact C has a transverse offset 34 near the center of the contact to provide that the right-hand-part of the contact C is raised slightly above its left-hand portion. This is to provide a desired bearing point for the contact against the upper side of an opening in the plug board for purposes to be hereinafter more specifically considered.

The left-hand portion 35 of the contact C is reduced in width to provide shoulders 36 on the opposite sides of the contact for limiting the degree of insertion of the contact C from the back of the plug board PB, the reduced portion 35 of the contact being of sufficient width to provide adequate eletcrical connection with the cooperating tip ill or 24 of the relay R, and being of sufficient width to be substantially biased by its resiliency to be maintained tightly against the supporting plug P. The left-hand end of the contact C is formed slightly downwardly at the point 31 to prevent the cooperating contact tip l8 or 24 of the relay R from striking the end of the contact C upon the coupling of the relay R to the plug board PB.

The plug P is formed of insulating material and has a's ubstantially rectangular shape. The width of the plug P is slightly greater than that of the contact C to provide for the fitting of the plug into the slots 63 in the opposite sides of the opening 2'! in the plug board PB. The longitudinal ribs 38 are so spaced on the opposite sides of the center of the plug P as to center the contact C longitudinally over the plug P by properly locating the detent 32.

A slot 39 along the longitudinal center of the plug P is provided to allow the insertion of a suitable tool such as the tool 40 shown in Fig. 10, 9 remove the detent 32 from its engagementwith a t e ehhhe an ed e tthen t 41 teiiae itate the insertion of the contac A ;PQ% t v i a. M UTiEQmG h QJ Qtf Q!- th h e-4 tota ed the. "up er p1 tm a Qr Qn' h s d5 h e st er ,n ee-itm 4 th tit-t PM! t e teeming: ete hat why to. the 1. .1u

eh q eth te d. 81.0w thawin 9" x n qqqitfh l strata and de ibe i g 21 fp l mg d-i in -theplug board P13 n eeehynlu i and; eehtaht, v manizh iqn is us n ar thah hht ahpe hefm t h plug .Q nd r haput ps Qfrp wid'hgh hens meter he es t ve ir n -.4 one a d; e-mp de ah mh tsv 48.; se if, 5) .t limi jthei'e teht hi the hs rthh tith espeh e .deht e e ir-0m .-t i .t ilh e rtan i d ce th m sl .il t iwi fi sth h shentr uit d a ht he-q mhn h uqi wtllsmetalt a ts ee iq r l es, I .hflup l i PF Q-Q SPl SQ-m y above. mehti h dh r r. p n t-w sens ese h r I nsu ate t etwi hefl hneet oh ga st such short circuiting b3! the-use. oi; sieev ng of insulating smatei iah The sloping su faces fi e 4) i n c hix nihe' nthh plu board BB1 redi' oe .the opening .21 to fsnialle sttsize at v e r hto th a d h adu l-reflu tioh; o the opening iacilitating the insertionof the oon tacts-Cin their respective slots.

o Thet ss -th o the l Pto heme-h ard Phtip i qcqmplished b e i ert on I o h f'n ug Bin; the oppositely spaced slots e63 (seams- 3 along oppositesides of the opening 21, such plug be ng {inserted nntil the, abutments 43. strike the h ht- Of the ua o dl nd b i Pe mane tl t a in thse sl 1 a by he-lee fe ement 'At tta hm n i h h re tt a qhtact M hi ab m er a the QMQfihhOESWh wires to the shoulders 3 00f that. contact the QQQWP' ma be n er e n as et prmed. abov e, Pl s. P, u h. nta t be n he te,d 9m h e o he P u hearth 1 9 2 th eh h m ets a 8. limi ts iih sxti h, t thismin the etestf h h ht qth e s eh nd..t e Qt ut: ments 4} of the plug and seeureiylocksthe contact against'backward movementw In a similar manner a contactG can be insertedin-a siot formed opposite thelower-surface-of--the-p1ug--P; such contactbeinginverted so that the in-11: insertion. of the contact-into its slot allows the detent 32 to spring upwardly past the .abutments 4] as shown in Fig. 4.

The contact 0 when-inserted intheiplug. board PB t applies .pressure:. by its s-resilieneyn at three bearing points in a mannen to; urge the; detent 3.2- iagain'st ithe suriace-eoi the: plug; Pabehind the s vha e:

e5 shse en-..wit J in; fact thepoint Sit-acts ash-a, fulcrum if an at;-

aznannertmurse-the:leit+ Q :actaQ tishtlywagainstitne the plush." :is more. cleanly,- illuswhic sh ws the contact (limits wtez then vis lflii .nsne. .vspqsitinn with, tin-upper b arin lYSQcfiEfijflfiirt e-upper side oisthe 'openin .21 1 .1th ynl e -bq rdtfifig a lowerwbear na poi t .5 I1 a aimtthe surface ofsthe plugl'P at the ri t- ;hand e dvof the detent 32, and another: lower 3 P Q nt*52w agai1nst,the boss Mrnear the i ahdcendtotithe nteet C. v

his rneans ofsupport for the contactC; has yeralijadva itagess; One ofwhich is that, :the

ter al; 0 th contact; thus insur n that thesend of the contact is always protected by the end-14.1 .QL he plus: B :as'a nst its striking a contact tip :18, or 24-:of; the-helayzliupon the coupling of, that .v hezn srbeard PB. An ther. advantage is hat byysuchyan or aniza i n, any force an- 91 d-a-tthe i ightehandend' of'a contact C toraise to -low ei thatend can in no way effecta reduction intthe ress eurging fthespping detent 31in. en-

ezahutments 4 l of? the; plugi P..

tempt ;is madeto raise the right-hand end of t e-t na Qt; Q, aw y from the plus toapply increase pressure to: the spring detentflzpand also ,to the lleit-hand end ofthe contact C atthe point ;y5,2 Likewise the;.app1i cation of pressure atsthemight-hand end ofthe contact; C in the oppositeedirection: is obviously efiective to increaseithe pressure of the spring detentfls It "35-. is therefore provided that a force, applied to-the righ'bghandyfindOfithG contact- Glas bythegpulle ingot; the; wires connectedj.-thereto either; imthe same, direction" or in; the opposite direction to the tense mgingwthe detent 32;against,the plug 40. P to insure against themontaet Citbecomingdisiwithdnaw immitsnormalp sition: iotranypre son theieft-h m end of:.;;the tww rn" to; raised upwardly as-,-:fonex+ sin s-na h intszleaningtheaplugaboard cola Rnr mov d; the po nt 54 fi1t nlu zhoar B would; acttas;a-zf lcrumrtd in.- stease. he imas re, of: the p ing detent- 32r-and engaged; i tom, itsa lockedzposition and becoming hus .a nsnreaeainst: th c ntact-Q beeomin tdise Weed a Inasmuchas it is at: times desirable touremoye- 5&5 assoeiatedm h by; the inserti n; ofua suitabl hei e nt Lofathe .ontaot Giazndthe asso a ed lus B initheislotj3t9sofixthat 1 18;: Asi'hasbeen e etofore poihtediout; it is desirable,thatix nly 5 nd} CUR? m atihh va ,cstltucture maw'zringqla specials tool 3 for? the release; of the detents of-isueh -contactsisuchi tool beingvofsa structure different from that oi -thermoreroom 70' readilyeinserted withimthemelativelymarrow slort 3.9tzoiia. p g; -i .l@=';hi h11 ofzttiieiri htehand end 50f thetco-ntaet removing tool-fiugis preferably slightlygiceater than th'eedepthwof the slotzw39zof the: plug; P; plqsithesheight :yof. the* abu-tI'ne-nts; ll

PDQ, ctrCj isurgedagainst theplug P-nearlthe {15 end .Qfdthe ontact, by'theresihency of 1311113:-

The right-hand end of the contact removingtool has a tapered cam surface for raising the detent 32 of the contact C upon insertion of the tool 4|] in the slot 39 of the plug P beneath that detent from the back of the plug board. When the tool 40 is fully inserted under the detent 32, the contact C can be readily removed by pulling lightly on the wires associated with that contact, thus causing the escapement of the detent 32 from its normally locked position behind the abutments 4|. It will be noted by the difference in the height of the abutments 4| and the ribs 38 of the plug P, that the disengagement of the detent 32 can be effected without requiring such detent to be restored entirely within the portion of the contact C from which it has been out.

As a modification of this embodiment of the present invention, it is illustrated in Figs. '7, 8 and 9 that solderless connecting sleeves can as well be either adapted to the contact C or formed as a part thereof if it is required in practice that solderless connections be used rather than the soldered wiring connections as has been specifically described. With reference to Fig. 7, at the right hand end of a typical contact C, a sleeve 58 is formed of a diameter for receiving the bare end of a wire 59, and a sleeve 60 is formed of a diameter for receiving the insulated end of the wire. The wire is clamped securely within these sleeves by a suitable crimping tool preferably forming transverse pressure points Bl as illustrated in Figs. '7 and 8. It is to be understood that the inside surfaces of the sleeves may be ribbed to more securely lock the wire within the sleeve if desired in accordance with the requirements of practice in the use of solderless connectors. Fig. ,9 illustrates how the round sleeves of the solderless connector are flattened by the crimping operation.

By allowing the wires to be attached to the contacts C prior to the insertion of the contacts C into the plug board PB, it is provided that such wires can be secured to the contacts C at a more convenient stage in the wiring of the electrical apparatus in that the contacts C can be attached when held spaced from adjacent wires and in the most convenient position for an operator to s0lder,-thus reducing the possibility of damaging other wires or other contacts in the soldering operation. It is also by allowing the attachment of the wires to the contacts C before their insertion into the plug board PB that it ispractical to use the solderless connectors. Wires can be attached by such solder less connectors to the greatest advantage where they can be taken to a machine having dies formed particularly for crimping the sleeves with the desired amount of pressure. Although hand tools are provided for crimping sleeves of solderless connectors, it is impractical to use a tool of this character in securing wires to contacts that are permanently secured in a plug board because of the relatively close spacing of adjoining contacts.

Having thus described a particular plug coupler organization having contacts quickly attachable and detachable to a plug board as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate the disclosure of the invention rather than to limit the number of forms which the invention may assume, and it is to be further understood that various adaptations, alterationsand modifications-may be applied to the specific form shown to meet the requirements of practice without in any manner departing from the spirit or scope of the present invention except as limited by the appending claims. What I claim is:

1. In a plug coupler of the character described for detachably supporting an electro-responsive device providing plug coupled electrical connections for a plurality of pairs of spring contact tips on said device, the combination with a plug board of insulating material having openings opposite said pairs of contact tips and a plug of insulating material secured in each of said openings, said plug having a portion protruding from the front of the plug board separating said contact tips of each pair, said plug having a transverse abutment and two laterally spaced longitudinal abutments in both its upper and lower surfaces within the opening in the plug board, and said plug cooperating with said plug board to form a slot extending through said plug board substantially opposite each of said contact tips above and below said plug, of a contact strip formed for the attachment of a plurality of wires at one end and receivable in said slot from the back of the plug board with wires attached thereto to a limited extent permitting the other end of the contact strip to be supported by the protruding portion of said plug so as to make electrical connection with one of said contact tips when said device is plug coupled to the plug board, said contact strip having a longitudinally extending detent formed therein of a breadth to be held in longitudinal alignment in said slot between said laterally spaced abutments of said plug, said detent being compressible upon insertion of the contact strip in said slot from the back of the plug board and being effective to lock said contact strip against removal from the back of the plug board by engagement with said transverse abutment of said plug when said contact strip is fully inserted.

2. In a plug coupler for detachably supporting an 'electro-responsive device providing plug coupled electrical connections for a plurality of pairs of spring contact tips on said device, a plug board of insulating material having openings formed therein opposite the respective pairs of contact tips of said device, a plug of insulating material receivable in each of said openings from thefront of the plug board only to a limited extent, said plug having a tapered end protruding from the front of the plug board when in its inserted position for spacing said contact tips of each pair, said plug having formed therein transverse abutments in its upper and lower surfaces, and said plug when inserted cooperating with said plug board to form slots extending through said plug board above and below said plug, and a contact strip formed for the attachment of a Wire at one end andreceivable in each of said slots from the back of the plug board subsequent to the attachment of a wire thereto to a limited extent wherein the other end is supported by said protruding portion of said plug and makes electrical connection with one of said contact tips, saidcontact strip having a longitudinally extending spring detent formed from its mid-portion compressible upon insertion of the contact strip in either of said slots and effective when said contact strip is inserted in said plug board to its fullest extent to lock behind one of said abutments of said plug and thereby lock said contact stripiagainst. removal from the backof the plug board and lock said plug against removal from the front of the plug board.

In a plug coupler for detachably supporting an electro-responsive device having a plurality of pairs of contact tips, a plug board having an opening therein opposite each of said pairs of contact tips, a pair of contact strips receivable in said opening, each of said contact strips havinga longitudinally extending spring detent formed from the mid-section thereof, and each of said contact strips having one end formed for the attachment of wires and having the other end formed of reduced width for insertion through said opening from the back of the plug board to make electrical connection with one of to a limited extent between said contact strips,

said plug having upper and lower transverse abut ments cooperating with said detents of the contact strips respectively above and below said plug to lock such contact strips in their fully inserted positions against removal from the back of the plug board and to lock said plug in its fully inserted position against removal from the front of the plug board, said plug having upper and lower longitudinal slots extending through and below said abutments whereby a tool can be inserted to release the locking of the detents of the respective contact strips and permit the removal of said contact strips without detachment of their associated wires from the back of the plug board, irrespective of whether or not there is a device coupled to the front of the time.

4. In a plug coupler providing quickly detachable connections to a plurality of pairs of contact tips of an electro-responsive device, a plug board having openings opposite the respective pairs of contact tips of said device, a plug of insulating material secured in each of said openings, said plug having a protruding portion extending from the front of the plug board sufficiently to separate the contact tips of a pair on said device, said plug having upper and lower transverse plug board at that abutments formed therein within the associated opening in said plug board, and said plug cooperating with said plug board to form a slot ex tending through said plug board above and below said plug, and a contact strip of resilient material receivable in said slot from the back of the plug board with a wire attached thereto to an extent permitting the support of one end of the contact strip by said protruding portion of said 10 plug and permitting an electrical connection of said contact strip with one of said contact tips, said contact strip having a longitudinal detent formed therefrom eifective upon insertion of said strip in said slot from the back of the plug board to lock behind one of said abutments against backward movement of said strip, said contact strip being formed with a transverse off-set at an intermediate point between the point of support by said protruding portion of said plug and the point of engagement of said detent behind said abutment whereby said contact strip is maintained in three point suspension within said slot, and said contact strip having a terminal portion formed therein extending from said off-set for the attachment of a wire.

JOSEPH F. MERKEL.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,060,761 Landers Nov. 10, 1936 2,111,118 Lake Mar. 15, 1938 2,143,645 Carson Jan. 19, 1939 2,158,004 Douglas May 9, 1939 2,222,252 Cochran et a1 Nov. 19, 1940 2,258,122 Merkel Oct. 7, 1941 2,279,915 Cram Apr. 14, 1942 2,318,648 Penfold May 11, 1943 FOREIGN PATENTS Number Country Date 537,968 Great Britain July 15, 1941 

